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- import { AttributeAction, SelectorType } from "css-what";
- const procedure = new Map([
- [SelectorType.Universal, 50],
- [SelectorType.Tag, 30],
- [SelectorType.Attribute, 1],
- [SelectorType.Pseudo, 0],
- ]);
- export function isTraversal(token) {
- return !procedure.has(token.type);
- }
- const attributes = new Map([
- [AttributeAction.Exists, 10],
- [AttributeAction.Equals, 8],
- [AttributeAction.Not, 7],
- [AttributeAction.Start, 6],
- [AttributeAction.End, 6],
- [AttributeAction.Any, 5],
- ]);
- /**
- * Sort the parts of the passed selector,
- * as there is potential for optimization
- * (some types of selectors are faster than others)
- *
- * @param arr Selector to sort
- */
- export default function sortByProcedure(arr) {
- const procs = arr.map(getProcedure);
- for (let i = 1; i < arr.length; i++) {
- const procNew = procs[i];
- if (procNew < 0)
- continue;
- for (let j = i - 1; j >= 0 && procNew < procs[j]; j--) {
- const token = arr[j + 1];
- arr[j + 1] = arr[j];
- arr[j] = token;
- procs[j + 1] = procs[j];
- procs[j] = procNew;
- }
- }
- }
- function getProcedure(token) {
- var _a, _b;
- let proc = (_a = procedure.get(token.type)) !== null && _a !== void 0 ? _a : -1;
- if (token.type === SelectorType.Attribute) {
- proc = (_b = attributes.get(token.action)) !== null && _b !== void 0 ? _b : 4;
- if (token.action === AttributeAction.Equals && token.name === "id") {
- // Prefer ID selectors (eg. #ID)
- proc = 9;
- }
- if (token.ignoreCase) {
- /*
- * IgnoreCase adds some overhead, prefer "normal" token
- * this is a binary operation, to ensure it's still an int
- */
- proc >>= 1;
- }
- }
- else if (token.type === SelectorType.Pseudo) {
- if (!token.data) {
- proc = 3;
- }
- else if (token.name === "has" || token.name === "contains") {
- proc = 0; // Expensive in any case
- }
- else if (Array.isArray(token.data)) {
- // Eg. :matches, :not
- proc = Math.min(...token.data.map((d) => Math.min(...d.map(getProcedure))));
- // If we have traversals, try to avoid executing this selector
- if (proc < 0) {
- proc = 0;
- }
- }
- else {
- proc = 2;
- }
- }
- return proc;
- }
- //# sourceMappingURL=sort.js.map
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